Sulfites (or sometimes spelled “sulphites”) are a family of preservatives that are commonly used in foods and medications. Although for most people they are not a problem, for some ingestion of sulfites can result in adverse reactions. In some people, they can cause headaches, abdominal pain, asthma attacks and nausea. In the most severe cases, eating food containing sulfites can cause a life threatening anaphylactic reaction.

Avoiding sulfites can be a challenge. They are in a wide variety of processed foods, and can even be sprayed on uncooked meat, fruit, and vegetables. Learning to read labels and understanding where the risks are will help you manage this difficult allergy.

Check Labels to Find the Sulfites

If you suffer from sulfite allergy or intolerance avoid any food that lists the following in the ingredients.

sulfite or sulphite, sulfiting agent, sulphiting agent

sulphurous acid

sulphur dioxide

potassium metabisulphite

sodium metabisulphite

potassium bisulphite

sodium bisulphite

sodium dithionite

sodium sulphite

Look for Hidden Sulfites

Labeling laws, in Canada, currently require the producer of a product to list any sulfites they add to their product. However, they are not required to list sulfites that may already be present in an ingredient. For example, sulfites will likely be present in glucose, a common ingredient in any sweet processed food. If you see glucose on an ingredient list there will likely be sulfites present.

Here are some examples of ingredients that may contain sulfites. Keep in mind this is not a complete list.

Sulfites in Medication

Sulfites can also be hidden in medications. Talk to your doctor and pharmacist about the ingredients in any medications you use. Remember to check both prescription and over the counter medications. Even some eye drops used during eye exams can have added sulfites, as well as dental freezing. Make sure all your health care providers understand your allergy. Don’t hesitate to ask questions before any medication is used.

Avoid Prepared Foods that May Contain Sulfites

Sulfites are approved for use on table grapes and on precut raw potatoes. They can also be present in prepared food that you might find in a vending machine or at the grocery store. Although it is not approved for salad bars, restaurants have been known to spray the vegetables so they stay fresh-looking. If you are eating out ask questions about what is in your food. If possible speak to the manager or the chef before you go to a restaurant.

Track Sulfite-Related Symptoms

Many people who have a sulfite intolerance can take in small amounts and not suffer any serious symptoms. Keep a food journal to track what you eat and any symptoms you experience. That way you can better determine what is safe for you. In some cases, complete avoidance is the only option. If this is your situation your best bet is to eat fresh home made food as often as possible.

Sulfite allergy can be particularly challenging to manage as it is not always clear on food labels if there are sulfites present or not. Many manufacturers are making the effort to inform you if there is a risk but not all do. Proposed changes to labeling guidelines will benefit those people who suffer from sulfite allergy and intolerance. However, until labeling guidelines become more stringent make sure you protect yourself by knowing where the hidden sulfites can be.